This invention relates to a device for receiving and/or transmitting electromagnetic radiation.
A portable receiver or transceiver device is known from EP-0 214 806 A2 which carries out its reception with a plurality of antennas. This portable transceiver device comprises a narrow-band, planar strip conductor antenna which is connected to a first receiver. Furthermore, a wide-band rod antenna is connected to an associated switching unit, and a second receiver and a transmitter are both connected to the wide-band antenna via the switching unit ("duplexer"). The planar strip conductor antenna is formed from a conductive radiating plate (layer) with a conductive ground layer or plate. The two are interconnected by a conductive connecting plate or layer. A housing surrounding the transmitter and receiver comprises an earpiece and a microphone in its front and the strip conductor antenna under its rear surface. The rod antenna is mounted vertically on the upper side of the housing.
The plurality of antennas used in this portable transceiver device has the object of reducing fading and noise effects in the reception mode. It is the object of the use of two different types of antennas to ensure that the antennas will not adversely affect one another and that the portable transceiver device does not become unnecessarily heavy and cumbersome.
U.S. Pat. No. 4,721,962 discloses an antenna for a transceiver device which requires no transmitter/receiver switching unit, typically a cordless telephone. This antenna is formed by a printed circuit board which is subdivided into three mutually adjoining regions by two separating gaps which lie in different planes. These regions are a first end region, which adjoins a first gap, a second end region which adjoins a second gap, and an intermediate or central region between the gaps. Electrically conductive surfaces or conductor tracks are connected across the gaps by means of elements having a high impedance to high frequencies such as, for example, high-ohmic resistors or choke coils. A high-frequency unit is preferably arranged below the central region of the printed circuit board and comprises a transmitter output stage which is connected to a first of the regions of the printed circuit board, which forms an antenna, while the intermediate region and the other end region of the printed circuit board form the director and reflector element, respectively. A receiver input of the high-frequency module is connected to the other end region which forms a receiver antenna, while the intermediate region and the first end region form a director and a reflector element, respectively. The high-frequency connections to the respective antennas are arranged adjacent the separating gaps.
This antenna arrangement is designed to be particularly suitable for use in portable (cordless) telephones, having the advantageous properties of a rod antenna while requiring no additional space in the housing of the telephone and comprising no parts projecting from this housing. A plurality of, for example, receiver antennas for a simultaneous reception with the purpose of suppressing noise and fading, however, is not formed by this antenna arrangement.